Lymphatic vessels serve an essential function in maintaining interstitial fluid balance throughout the body. They also serve as a conduit for the trafficking and maturation of immune cells. Functional disruption of lymphatic vessels by either surgery, radiation/chemotherapy or organ damage results in pathological lymphedema and subsequent interstitial fibrous deposition and inflammation. The heart contains a dense network of lymphatic vessels that exhibit coordinated flow with each contraction of the myocardium. However, whether lymphatic dysfunction contributes to the pathophysiological progression of heart injury following myocardial ischemia remains unknown. Furthermore, we lack a full understanding of the consequences of myocardial edema on heart function following ischemic heart disease. Therefore the overall goal of this research proposal is to develop sophisticated surgical and genetic mouse model tools to address the function and modulation of cardiac lymphatic vessels in heart disease. Based on our expertise in lymphatic vessel biology and our interest in the cardioprotective functions of adrenomedullin peptide, we feel that we are uniquely well- positioned to address the effects of either increased cardiac lymphatics or lymphatic insufficiency on the resolution or exacerbation of myocardial edema, respectively. Results from our studies will provide conceptually novel insights into the largely unexplored role of cardiac lymphatic vessels in myocardial edema.